Method of manufacture for brick or block greases



Patented. Aug. 5, 1941 S PATENT OFFICE METHOD OF MANUFACTURE FOR BRICK OR BLOCK GREASES Lorne W. Sproule and Edmund J. Higgins, Sarnia,

Ontario, Canada, assignors to Standard Oil Development Company, a corporation of Delaware No Drawing. Application December 5, 1939, Serial No. 307,586

4 Claims.

This invention relates to lubricants for use on open bearings at high temperatures, particularly a lubricanthaving a high melting point and a long life, when subjected to the high-temperatures at which the bearings of heavy machinery usually operate.

In cement mills and paper mills, the machinery has certain parts that are subjected to sensible heat and therefore the bearings usually onerate at temperatures of 150 to 250 F. and sometimes higher. To lubricate these bearings, greases which have been dehydrated completely by heating up to 500 F. are used. In the preparation of greases of the required high melting points, they are dehydrated'by maintaining for several hours at temperatures up to 500 F., after which the molten grease is run'into iron pans of such size that after cooling blocks of grease that will fit the grease caps on drier roll bearings may be cut from them withoutwaste. The greases are generally composed of a mineral lubricating oil, fatty oils or acids and caustic soda. Often a mixture of caustic soda and lime is used to saponify the fatty materials. It is at times very diflicult to obtain a homogeneous mixture of compositions of this type for, after they are poured into the molds or iron pans, there is a tendency for the grease on cooling to form cores ranging from pock marks to hollow cylinders.

An object of this invention is to provide a composition which on cooling will not tend to ture, after it is heated to dehydrate for a suitable time such as 1 or 2 hours, is then mixed with 5 to 20% of a vegetable wax, such as candelilla or other wax having an acid number of less than 20. candelilla wax is preferred. After a uniform composition is obtained, the hot mixture is then run into iron pans or molds which on cooling forms blocks of grease of the desired melting point. The melting point may be varied between 300 and 400 F. by varying the compositionand time of heating.

A suitable formula or a mill grease prepared according to this invention is one containing 15% of stearic acid and rosin soap, 10% of candelilla wax and of a mineral lubricating oil having a Saybolt viscosity at 210 F. of 100 seconds and a viscosity index of 72.

The addition of candelilla wax improves the grease by acting asa plasticizer preventing the crystallization of the rosin and stearic acid soaps, keeps the grease homogeneous and prevents the weeping and sweating of the oil on standing or in use.

It is not intended to limit this process and lubricant to candelilla wax as other waxes having a free acid number less than 20 can be used. If the wax is added before the saponification of the fatty oils or acids is obtained and the free fatty acid of the wax neutralized, the finished product is not as homogeneous in its structure as one to which the wax had been added after saponification was completed, although-it did show a better structure than one to which no wax had been added.

We claim:

1. A lubricant having the following formula: 10 to 20% of soda soaps of stearic and rosin acids, 5 to 20% of a vegetable wax having an acid number of less than 20 and 60 to of a mineral lubricating oil having a Saybolt viscosity at 210 F. greater, than 60 seconds.

2. A'lubricant comprising 15% of a mixture of sodium stearate and sodium rosinate, 10% of candelilla wax and 75% of a mineral lubricatin oil having a Saybolt viscosity at 210 F. of 100 seconds and a viscosity index of 72.

3. A method of preparing a mill grease which comprises saponifying a mixture of fatty and rosin acids with soda, heating the mixture of soaps i'n a mineral lubricating "oil and adding to the heated mixturea vegetable wax having a free acid number of less than 20 and cooling without saponification oi the wax.

4. A method of preparing a mill grease which comprises heating 15 to 20% of a mixture based on the finished product of equal parts of stearic acid and rosin with suflicient caustic soda to-saponiiy the stearic acid and rosin and 50 to of a mineral lubricating oil until saponiflcationand dehydration is complete, then adding 5 to 20% of a vegetable wax having a free fatty acid number of less than 2'0, pouring into molds and allowing to solidify by cooling. 7

LORNE w. SPROULE.

EDMUND J. HIGGINS. 

